Name: From: file:///D:/Samples/TestUpdatedVersion/bin/Debug/TestUpdatedVersion.vsto
The customization cannot be installed because another version is currently installed and cannot be upgraded from this location. To install this version of the customization, first use Add or Remove Programs to uninstall this program: TestUpdatedVersion. Then install the new customization from the following location: file:///D:/Samples/TestUpdatedVersion/bin/Debug/TestUpdatedVersion.vsto
************** Exception Text ************** Microsoft.VisualStudio.Tools.Applications.Deployment.AddInAlreadyInstalledException: The customization cannot be installed because another version is currently installed and cannot be upgraded from this location. To install this version of the customization, first use Add or Remove Programs to uninstall this program: TestUpdatedVersion. Then install the new customization from the following location: file:///D:/Samples/TestUpdatedVersion/bin/Debug/TestUpdatedVersion.vsto at Microsoft.VisualStudio.Tools.Applications.Deployment.ClickOnceAddInDeploymentManager.VerifySolutionCodebaseIsUnchanged(Uri uri, String subscriptionId, Boolean previouslyInstalled) at Microsoft.VisualStudio.Tools.Applications.Deployment.ClickOnceAddInDeploymentManager.InstallAddIn()
You can try to delete a registry key located at:
HKEY_CURRENT_USER\Software\Microsoft\VSTA\Solutions\{GUID}
The value of {GUID} will be different on your environment.
Check to ensure that you're deleting the right key. Confirm by checking the DWORD "Url" value at the key.
Restart Excel and you should be good to go.